Method of treating resins



March 21, 1933. D w HOGE METHOD 0F TREATING RESINS Original Filed Dec l llllll ||llll l l I l 1.1 llllllldllllllll 4 /lll IJ.

Patented Mar. 21, 1933 UNITED .STATES PATENT oFElcE DANIEL W. HOGE, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO CARLOS W. NEWBE'RY,

F LOS ANGELES, CALIFORNIA i 'METHOD or TBEATING RESINS Application led December 19, 1928, Serial No. 327,013. Renewed August 26, 1932.

This invention has to do with distillation systems, and relates particularly to a method for treating resinous materials by distillation and thermal decomposition or cracking of crude resins, to produce relatively light and volatile liquid products.

The present system is adapted to be appliedto the treatment of resins commonly found in many species of plants, for instance coniferae, which specie comprises the various kinds of pine trees. It has been found, however, that the system is particularly suited to the treatment of rosm contained in the exudate obtained from in extract from dead trees, and known as crude turpentine, the rosin being obtained from the crude exudate as residue after the lighter turpentine fractions, or spirits of turpentine, are distilled ofi'. will, therefore, describe the invention as applied to the treatliving pine trees, or

ment of this particular resinous material.

It will be noted that the term Aresin applies to a general classification of secretions from a variety of types of plants and that the word rosin refers particularly to the hardened residue obtained'from crude tur- E pentine as described.

\ view, therefore,

Due to the great -demand and production of refined turpentine there is necessarily produced a vast supply of rosin which, heretofore, has been of comparatively less value and more or less restricted as to itsiuses. In

of the desirability of utilizlng the residual rosin to its greatest possible extent, I have provided the present method vfor treating rosin to produce a variety of products having a wide range of utility, and which may be produced most economically, especially in view of the' present low cost of crude rosin.

By means of the present system, which will later be described in detail, there is produced from common gum or wood rosins,

awhich are of course solid, a series of liquid products ranging in boiling point, generally speaking, from about 80 F. to 600 F., the

average gravity ofV these products being around 35 B. As typical examples of uses to which certain of the products are particularly well suited, a few may be given and the corresponding product or cut may be identiiied according to its boiling range. Thus a fraction having a boiling range of 170o F. to 325 F'. is suited for use in the manufacture of lacquers as a gum solvent, and a cut, 80 F. to 375 F. serves to render ordinary gasoline non-detonating when about 10% by volume of the rosin product is`mixed with gasoline. It is necessary in preparing lacquers that a suitable material, commonly termed. a'plasticizer, be added for rendering the dried lacquer suiiiciently flexible to reasonably withstand impact without `shattering,'andfor this purpose afraction between 37 5 F. and 480 F. may be added to 65 thelacquer mix to give it, when dried, the aforesaid property. Various fractions may be selected for use in preparing paints, varnishes and the like, and it is unnecessary to enumerate their various uses in detail. 70

The present system for treating rosin and the manner of Aobtaining the above named products will be understood mostl clearly from the following detailed description, thereof, reference being made in the description to the accompanying drawing in which there is shown diagrammatically a typical form of apparatus for carrying out my process.

Numeral 10 in the drawing indicates a retort or still which may be of any suitable d esign, and which is adapted tobe charged with solid rosin preparatory to starting operations. The still is' heated to suficient temperature to vaporize the rosin, or, more prop- 85 erly speaking, to decompose the rosin and to cause products of decomposition to be liberated in the -form of vapor. That thermal decomposition of the rosin takes place is evidenced by the fact that the melted rosin in the still is at substantially higher temperature than the vapors rising therefrom. As will later be described, vapors may pass from thev still either through line 11 to the tower 12, or they may be conducted through line 13 to the superheater or cracking still 14, by correspondingly adjusting valves 15 and 15a; Satisfactory operation is had by maintaining a shell still temperature of from about 550 F. to 800 F.,`which may be considered as 100 typical, and usually it is not necessary to apply pressure to the still, although moderate pressures,l say up to 25 lb. per sq. in. may be used. i

Although any suitable form of superheater may be embodied for heating thevapors from still 10, I prefer to use the particular form ofsuperheater shown. The superhe'ater embodies, briefly, a concentric double pipecoil 16, the various units or lengths 16a of which are connected in series by means of suitable fittings 17 the coil being mounted on suitable baille or end plates 18 in such a manner that the fittings are contained within the spaces S between the end plates andthe brick work 19, s'o as not to be exposed to the hot gases within the combustion chamber C through which the concentric pipe units 16a extend. As describedin the referred copending application, the two concentric pipes in each unit are spaced, and the space between them illed with lead in order that the inner pipe, through which the vapors flow, may be subjected to even temperatures throughout their lengths during operation, and thereby preventing the deleterious effects of local overheating. ticularly satisfactory for the present purposes in that it may be employed to effect superheating and cracking of the vapors with minimum depositing in the tubes of carbo'- naceous or coky materials.

Thus the vapors from the shell still' are subjected, to cracking in the resultant breaking down of the molecular structure of these vapors to produce relatively light vapors which, when condensed, result in a liquid product having-a comparatively wide range of volatility. The cracked vapors from line 20, and' thence either through line 21 into the tower 12, or through line 20a to suitable condensing or fractionating apparatus.

In some instances the entire vapor stream in line 20a may be condensed and treated as product, or any suitable .fractionating means may be employed for fractionating the vapors to produce cuts corresponding to fractions of the said liquid product obtainable by complete condensation. "As typical means, for producing the desired liquid fractionation, I have illustrated the condenser 22 and what may be considered either as partial condensers or fractionating columns 23 and 23a, of which there may b e any suitable number. By the system of piping shown, the vapors may beV passed directly through line 24to condenser 22, or they may be by-passed by way of lines 25 through the fr actionatingy columns, the products from which are delivered to the receivers R. Generally speaking the'cracking temperature ,in the superheater need not greatly Exceed 1100o F., and the pressure-preferably i.. maintained fairly low, say substantially This type of superheater is parthe superheater, with the superheater iiow through vapors 25 lb. per sq. in.

The tower 12, as previously mentioned, may receive vapors directly from still 10 by way of ,line 11, or from the superheater through line 21 by properly adjusting the valves indicated. The general purpose of the tower is to provide means for bringing the vapors intimately into contact with a suitable material which, by catalytic action, serves to atmospheric or below eHect further decomposition or cra-cking of the vapors, and for this purpose any desired form of tower may be provided. Although I have found that various catalytic materials, especially metals, may be employed for the present purpose, which catalysts vary according to their' relative efliciency decompositionbf the vapors, metallic aluminum has been found to be especially eective in cracking the vapors by catalytic action.- It will be understood that the metallic aluminum so used may -be of any suitable degree of ineness,`so long as the vapors have free access therethrough, and also that such metallic aluminum may be incorporated or included with other materials in effecting the decomposition reaction. In this regard, it lhas been found that such catalytic actionis had by a mixture of aluminum and nickel, but not to such aluminum alone.

i In the illustrated tower 12, thealuminum 27 in the form of shavings or common kinds of tower packing', is 'contained on a per'- forated grid 12a spaced at`28 from the bot-y tom, of the tower. Compara-tively heavy vapors from this space then 'flow upwardly through the aluminumv packing, the latter serving as a catalyst tov decompose the rising vapors. Whatever. condensate accumulates in the tower is led 'back9 into the still through line 29.'v The light cracked vapors from the tower flow through line 24a to the condensing` and fractionating apparatus,

wherein they may be treated as previously ture and pressure of the vapors in the tower A correspond to the source from which the are supplied, that is, vapors from the shell still pass through the tower aboutsuperheater temperature and pressure.

In the treatment of rosin by the present process, I have found that the vaporstream in eifecting the f los from the shell still may be passed directly into the tower and the vapors decomposed therein by catalytic action and subsequently fractionated, or the vapors maybe cracked by passing directly from the still through the` superheater and then fractionated.l In addition, these two steps may be combined and the vapors having been subjected to preliminary cracking in the superheater, may be further decomposed in thevtower and then fractionated as described.

It has been noted that the nature of the final productobtained is effected according to the particular manner in which the vapors from the shell still are subsequently treated, as evidenced by the following data which is typical of results obtained by passing the vapors through the tower, and in another instanceby subjecting them to cracking in the superheater alone. Thus a product representing the total condensate obtained from vapors passed directly from still 10 through the tower was found to have a boiling range of about 120 F. to 480 F. and to have a gravity of about 32 B. The product obtained condensing the entire vapor stream from the superheater was found to have a boiling range of approximately 80 F. to 375 with a'gravity of 38 B. the runs in which these products were obtained, the temperature of the liquid rosin in the shell still was increased from 620 F. to 800 F., and the, superheater temperature decreased from 1080 F. to 850 F.

The above tests and temperatures may be considered as typical of operating conditions and results obtained in the present system, although it will be understood that these may be varied within comparatively wide limits the quality of products in accordance with desired.

It may be noted that the products obtained by use of the shell still in combination with the superheater are of comparatively low boiling point, and therefore that products having comparatively high boiling points, as for instance, the previously mentioned fraction between 375 F. and 400 F. for use as a plasticizer lacquer preparation, is obtained from the fractionation of the condensate resulting from the treatment of vapors in the tower, which condensate has an end point of 480 F. or above. v

During the period in which the charge in the shell still is heated to suitable operating temperature, and during the early portion of a distillation, an acid liquid is obtained from the condenser, this liquid bein in the nature of a preliminary product o tion of the rosin and comprising a substantial quantity of acetic acid. The amount of acid llquid obtained under certain conditions represents about.15% of the total condensate l produced during a run. At the Conclusion of the production of the acid liquor, the more volatile of the oil roducts hereinabove mentioned are distilledl and their production continues until the still charge has been reduced to the desired extent, which extent may represent practically any percentage of the original charge.

I claim: 1. A method for distilling crude rosin that includes heating and vaporizing crude rosin During v decomposiin a vaporizinglzone,subjecting the vapors to cracking in a craclnng zone at a tempera- 1n a vaporizing zone at a temperature below 800 F., cracking the vapors in a cracking zone at a temperature not exceeding substantially 1100 F., and at a pressure not exceeding substantially 25 lbs. per sq. in. gage, and fractionating the cracked vapors to produce liquid fractions thereof.

4. The method of distilling crude rosin that includes, heating and vaporizing crude rosin in a vaporizing zone, conducting the vapors in a stream having a long path of flow through a asuperheated cracking zone in which the vapors are cracked at a temperature between 700 F., and 1100 F., and then subjecting the vapors to fractionation.

5. The method of distilling crude rosin that includes, heating and vaporizing crude rosin in a vaporizing zone, conductln vapors in a stream having a long path oflow through a superheated cracking zone in which the vapors are cracked at a temperature between 700 F., and 1100 F., maintaining the vapor stream during the cracking operation under uniform heating conditions whereby localized overheatin is prevented, and finally subjecting the cracked vapors tov fractionation.

In witness that I claim the foregoing I have hereunto subscribed my name this 2nd day of November 1928.

DANIEL W. HOGE.

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